The disclosure generally relates to a control circuit for a power converting circuit and, more particularly, to the control circuit with a reduced number of pins of the integrated circuit package.
As the dimensions of the electronic equipment are getting more and more compact, the dimensions of the electronic component within the electronic equipment must be reduced accordingly to fit in the limited space. For example, the integrated circuit elements often need several input pins and output pins for coupling with other circuit elements. Thus, a larger integrated circuit package is needed for having enough number of pins and the dimensions of the die are often far smaller than the dimensions of the package. The large-sized integrated circuit package is not only a waste of material but also cause environmental problems. Moreover, the dimensions of the integrated circuit elements may not be effectively reduced.
In the applications of the power converting circuit, when the control circuit of the power converting circuit is realized with the integrated circuit element. The die size of the control circuit is usually very small compared with the integrated circuit package. However, the control circuit requires a lot of pins for coupling with other circuit elements for configuring the power stage circuit, for receiving the feedback signals, for receiving the operational parameters, etc. Thus, the control circuit of the power converting circuit has to utilize a larger package for having enough number of pins. The flexibility and the dimensions of the control circuit are therefore limited.
Some circuit blocks of the integrated circuit elements may share the pin of the integrated circuit package for reducing the required number of pins and utilizing a smaller package. However, the differences between the circuit elements make it difficult to have a simple design rule for the circuit blocks to share the pin. When the circuit blocks of the integrated circuit elements need to share the pin of the integrated circuit package, it still should be precisely designed to ensure the circuit blocks may function correctly.